it would be the E320. Although one of the testing magazines rated the 240D the best way back when I feel the 300D turbo is the best. I average 25 mph city/hwy combined. I have not run a tank through it since replacing the timing chain and bringing the tire pressure up from 27. The only thing I would change would be to have a manual tranny in it. I have noticed that over the past 6 months the number of 240D's in listed for sale in the Atlanta paper have dropped ALOT.
Jim
'85 300D
'95 E320
'97 CRV